Hydronium Adsorption on OOH Precovered Pt(111) Surface: Effects of Electrode Potential

Using the Density Functional Theory-based total energy calculations, the hydronium adsorption on the OOH precovered Pt(111) surface is studied. The electrode potential is modeled by varying the electron affinity of the reduction center [OOH + H3O(H2O)](+). Two possible structures of this reduction center on the Pt surface are HOOH + 2H(2)O and 2(OH) + 2H(2)O. Evidently, the dissociation of HOOH into 2(OH) can be accomplished by changing the electrode potential to the higher value by 0.16 V. The activation energy for the dissociation is approximately 0.1 eV. The optimized structures are also obtained.